Support is being requested for four separate but related projects: 1) Neurobehavioral Effects of Lead Exposure in Children, 2) Social, Behavioral and Environmental Factors as Determinants of Excessive Lead Exposure, 3) Prospective Longitudinal Study on Serum Mineral "Calcium and Phosphate Metabolism" and Bone Mineralization in Infants and Children with Chronic Lead Exposure, 4) The Effects of Lead Exposure on Electrophysiological Measures of Brain Function. There also is a Core unit which is responsible for subject recruitment, medical services for the subjects, data management and statistical services, and analytical services. The subjects are inner city Cincinnati children recruited and studied from birth. Most subjects are already entered into the study with initial recruitment having begun 1/80. Recruitment will terminate fall, 1985 with entry of the 333rd child. Neurobehavioral studies (Project 1) have been ongoing from that time along with determination of blood lead and protoporphyrin 4X yearly. Lead in the children's physical environment also is characterized under the aegis of Core. This activity now assumes Project status by virtue of the introduction of behavioral, demographic and social measures as independent variables hypothesized to interact with environmental levels of lead exposure in determining the magnitude of lead intake by the same subjects as in Project 1. Projects 3 and 4 are new initiatives which propose to study calcium metabolism and electrophysiological expressions of brain function, respectively. Again, the subjects to be studied are from the cohort being studied in Project 1. Longitudinal psychometric measures and experimental measures of cognition are being made in Project 1. Chemical analyses being performed which are critical for all projects include 1) blood lead, 2) erythrocytic protoporphyrin, 3) serum iron and iron-binding capacity, 4) lead in housedust, soil, paint (XRF), 5) serum 25(OH)2D3, 1, 25(OH)2D3, calcitonin, calcium, phosphate. Other critical measures include bone mineralization and auditory and visual evoked potentials. Data analysis techniques to be applied include multiple regression, dose-response, dose-effect, multivariate analyses such as structural equations and strategies for causal modeling. Longitudinal analysis of the data via Random-effects models and/or Random Coefficient Regression models has also been undertaken.